Head rests for typewriters



A. DONOFRIO EI'AL 2,903,119 HEAD RESTS FOR TYFEWRITERS Sept. 8, 1959 3 Sheets-Sheet 1 Filed Nov. 14. 1958 N s MWNO U O N N D R E TL 0 VYEJ. T NNC .N

TWW NOL ALL Sept. 8, 1959 UONOFRIO ETAL 2,903,119

HEAD RESTS FOR TYPEWRITERS Filed Nov. 14, 1.958 3 Sheets-Sheet 2 INVENTORS ANTHONY D'ONOFRIO LOUIS CETRAN LLOYD J. LAPOINTE ATTORNEYS Spt. 8, 1959 2,903,119

A. D'ONOFRI O ETAL HEAD RESTS FOR TYPEWRITERS Filed Nov. 14, 1958 3-Sheets-Sheet 3 INVENTORS ANTHONY D'ONOFRIO LOUIS CETRAN LLOYD J. LAPOINTE BY Q1,

ATToNEYs United States Patent HEAD RESTS FOR TYPEWRITERS Anthony DOnofrio, Hartford, Louis Cetran, Newington, and Lloyd J. Lapointe, Manchester, Conn., assignors to Royal McBee Corporation, Port Chester, N.Y., a corporation of New York Application November 14, 1958, Serial No. 773,930

19 Claims. (Cl. 197-42) This invention relates to a novel construction and arrangement for typewriter head rests and more particularly relates to an improved apparatus for statically supporting a plurality of type bars and for reducing the amount of rebound occurring after each of said type bars has partaken of an operative stroke.

In normal operation after a type bar has completed its forward printing stroke it is power driven, as by a spring or the like, back to its normal position on the typewriter head rest. In order to reduce the time required for a full operative cycle of the typewriter, the said power means are adjusted to effect a rapid return stroke of the respective type bars. Under these conditions each rapidly returning bar will have a tendency to bounce or rebound after striking the head rest. The extent of such rebound in any given case may be sufficient to project a given bar into the path of movement of one or more of the subsequently actuated type bars thereby causing clashing and possible damage to the parts involved. Perhaps the most detrimental aspect of the above mentioned tendency for rebound is. that the maximum potential speed of operation of the typewriter is sharply reduced.

One object of the instant invention is to provide a typewriter head rest which is easily and inexpensively manufactured and which will substantially eliminate type bar rebound. I

Another object of the instant invention is to provide an improved construction and arrangement for a typewriter head rest which comprises two interconnected elements that are pivotally supported with respect to the typewriter segment.

Another object of the invention is to provide a novel head rest arrangement for a typewriter whereby any type bar returning to its normal position strikes a first impact surface and then strikes a second impact surface a predetermined period after striking said first surface.

Another object of the invention is to provide an improved construction and arrangement for a typewriter head rest whereby about all of the kinetic energy of any type bar which is rapidly returning to its normal position is transferred to each of a substantial number of the then stationary type bars of the machine rather than to only a relatively few of the adjacent stationary type bars.

Still another object of the invention is to provide an improved construction and arrangement for a typewriter head rest whereby the impact of any type bar striking the typewriter head rest causes an impulse to be simultaneously applied to. substantially all of the then static-nary type bars.

A further object of the invention is to provide a novel typewriter head rest construction and arrangement whereby the kinetic energy of any given type bar that is rapidly returning to. its normal position is dissipated by way of altering the vibrational characteristics of said given type bar.

Other objects and many of the attendant advantages of the invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:

Fig. 1 is a partial longitudinal sectional view illustrating the structural environment of the invention.

Fig. 2 is a perspective view of the instant head rest.

Figs. 3 and 4 are fragmentary side views illustrating the nature of the head rest shown in Fig. 2.

Fig. 5 is a perspective view of a second species of head rest.

Figs. 6 and 7 are fragmentary sectional side views illustrating the structural and operational nature of the head rest shown in Fig. 5.

Fig. 9 is a fragmentary side view showing the structural nature of the supporting means for the head rest of Fig. 8.

Fig. 10 and 11 are diagrammatic views illustrating the operational nature of the head rest of Fig. 8.

Referring to Fig. 1 a normal complement of type bars is pivotally secured, as at 7, to the segment 8 which is operatively mounted in the frame 9 of the typewriter. When any one of the typewriter keys 10 is depressed the action plate 11 is power driven by the serrated roll 12 such that the type bar 13 partakes of a clockwise or forward printing stroke. After this operative stroke has been completed the usual spring means or the like, not shown, quickly restores the type bar 13 to its normal position in engagement with the head rest of the type writer. When said type bar strikes the head rest it will rebound and may undesirably clash or interfere with other subsequently actuated type bars. The head rests contemplated by the instant invention overcome this difii culty by utilizing particular operational concepts which virtually eliminate the rebound tendencies of the type bars.

One species of the invention is illustrated in Figs. 1-4, only one type bar being here shown for the purposes of clarity. The head rest 15 comprises two arcuate elements 16 and 17 which are mutually interconnected at their respective adjacent ends by looped portions 20. The loop 21, Fig. 3, formed in each portion 20 surrounds a suitable stud 22' which is fixedly secured to the outer end of each of the support arms 23. Arms 23 are fixedly mounted on said typewriter segment 8 by any suitable means such as screws 24. It will be understood that the respective right hand ends, as viewed in Fig. 2, of elements 16 and 17 are interconnected and supported in a manner similar to that for the left hand ends thereof. The said studs 22 support the head rest 15 for pivotal movement about the substantially horizontal axis 25. The effective distances L and L Fig. 3, between the pivot axis 25 and the respective parallel vertical planes of said. head rest elements 16 and 17 are preferably different; for example the ratio of L to L may be equal to two. The various portions of the head rest element 17 underlie the intermediate region 26, Fig. l, of each of the normal complement of type bars, while the various portions of element 16' underlie the type head 27 of each of said type bars. A suitable coating of plastic material or the like may be provided on each of the elements 16 and 17 in order to reduce the noise level existant during opera-.

tion of the instant apparatus. Some of the type bars nor! mally rest so as to engage and be supported by the head rest element 16, while others correspondingly engage and. are supported by the element 17. In this way head rest. 15 is yieldably biased to one statically balanced rotative home position by the weight of the outer ends of the type bars. condition, is shown as supported by the element 16; the

associated portion of the element 17 being disposed In Fig. 1 type bar 13, in its normal at-rest.

a slightly below the lower edge of said type bar portion 26.

The converse is true for those type bars which are normally supported by element 17. The head rest 15 may be constructed as a single one piece unit as illustrated in Figs. 13 or may be composed of several individual parts which are fixedly secured together in any suitable manner. As will be apparent head rest 15 is simple in construction and is easily and very inexpensively fabri:

cated and assembled in the typewriter. v

A description of the effective operation of the instant head rest 15 will be made with reference to the motion of type bar 13; it being understood that said head rest and the other type bars cooperate in a corresponding manner. When type bar 13 is returning from a printing stroke it will first strike the head rest element 16. This will cause the head rest 15 to rotate to a slight extent in a counterclockwise direction, as seen in Figs. 1 and 2; the possible limit of said rotation being reached at or shortly after the time that the element 17 engages the lower edge of said type bar portion 26 as illustrated in Fig. 4. During this action the momentum of type bar 13 is dissipated by causing all of the type bars which are normally engaged with element 17 to receive an elevating impulse from the rapid but very short arcuate displacement of the cradled head rest 15. When a type bar which normally engages the element 17 is returning from a printing stroke to its normal at-rest position it will strike element 17 first and thereby impart a corresponding clockwise impulse to the head rest 15. As the serially actuated type bars successively strike head rest 15 during normal typing operations said head rest will partake of little more than an arcuate vibratory motion of almost imperceptible amplitude and will correspondingly vibrationally agitate the various type bars which are then engaged with the respective elements 16 or 17. The kinetic energy of each returning type bar is thus immediately dissipated by causing the vibratory motion of the various other type bars and the tendency for each such returning type bar to rebound is all but eliminated. It will be apparent that the head rest 15 will always return to and yieldably assume a normal rotative position such that the clockwise and counterclockwise torques about axis 25, caused by the repose of the various type bars on elements 16 and 17, are statically balanced.

A second species of the invention is illustrated in Figs. -7. Here again for the sake of clarity only one type bar of the normal complement is shown and specifically discussed, it being understood that the other type bars cooperate with the head rest in similar fashion. In Figs. 57 the reference numerals 30, 31, 32 and 33 respectively designate a segment, head rest support arms, a head rest element, and a type bar arranged and supported in a manner similar to that presently used in Royal typewriters. Added to this conventional type structure is a rigid second arcuate head rest element 34 which is fixedly secured by any suitable means to the said head rest element 32. The inner end of element 34 is bent upwardly and is provided with a plurality of laterally spaced slots 35 which define a plurality of rigid damping tabs or fingers 36 that respectively extend towards and terminate just below the lower edges of the various type bars. As may be seen from Fig. 6 the end of the tab or finger 36a associated with type bar 33 is normally spaced a short distance below the lower edge of the intermediate type bar portion 37.

Type bar 33, when in its normal at-rest or home position shown in Fig. 6, engages and is yieldably supported at its outer end by the rubber-like material 40 on the head rest element 32. When the type bar is operatively actuated and is then spring driven through a return stroke it will be arrested by first striking and locally deflecting said material 40. After the type bar has penetrated a short distance into material 40 the lower edge of type bar portion 37 will engage the upper end of tab 36a as shown in Fig. 7. Continued downward movement of type bar 33 will cause a deeper local penetration of said material 40 but the finger 36a will prevent the type bar portion 37 from partaking of a corresponding equal continued downward movement thus causing the outer end of the type bar itself to be laterally flexed downwardly to a slight degree with respect to the said portion 37. At the same time that part of the type bar 33 between finger 36a and the segment 30' tends to be flexed upwardly or in the opposite sense as that for said outer end of the type bar. When the downward movement of the type bar has been arrested by the resistance of head rest element 32 and the imposition of the secondary boundary constituted by the damping tab 36a the relaxing of the two above noted opposing flexures will tend to neutralize the type bar strain and will thus cause the kinetic energy of the returning type bar to be dissipated by being converted into a high frequency small amplitude vibrational flexure of the type bar rather than into the usual arcuate translato ry rebound movement thereof.

The normal distance between the lower edge of type bar 33 and the free end of tab 36a may be adjusted in accordance with the particular return speed of type bar, the relative position and degree of resiliency of the said material 40 and the desired length of time between the sequential engagement of elements 40 and 36 by a returning type bar. Fingers 36 may be coated with suitable plastic material to keep the operational noise level at a minimum.

A third species of the invention is illustrated in Figs. 8-11. Here the various parts 50, 51, 52 and 53 are respectively the same as parts 30, 31, 32 and 33 of Fig. 5. The head rest 54 here comprises a pair of arcuate elements 55 and 56 which are similar in nature to elements 16 and 17 shown in Fig. 1 and which may be covered with any suitable plastic noise inhibiting material. The respective mutually adjacent ends of elements 55 and 56 are rotatably mounted in an interconnecting link 57, Fig. 9, which is rotatably supported by stud 60 fixedly secured to the outer end of each of the support arms 51, 52. It will be understood that the right hand ends, as viewed in Fig. 8, of head rest elements 55 and 56 are interconnected and supported in a manner similar to that just described for the left hand ends thereof. As is best seen in Fig. 9 the inner portion of stud 60 is bent downwardly to a considerable extent so that theaxis of rotation of link 57 is disposed at an angle to a horizontal plane. Under these conditions when the links 57 rotate on said downwardly bent portions of studs 60 one of the head rest elements 55 and 56 will move upwardly and to the right while the other of said elements simultaneously moves downwardly and to the left, as viewed from the front of the typewriter.

Figs. 10 and 11 diagrammatically illustrate the operational nature of the instant arrangement. Normally the outed ends of the type bars on the left side of the segment 50 are supported by the left hand portion of one of the head rest elements 55, 56 while the outer ends of the type bars on the right side segment 50 are supported by the right hand portion of the other of said elements 55, 56. When any actuated type bar, for example one on the right side of segment 50, is returning to its home position it will first strike the head rest element 56 by which it is normally supported. This impact will set up an unbalanced torque of said elements 55, 56 about the pivot studs 60 and the resultant rotational movement of links 57 will cause element 56 to move downwardly and to the right as indicated by arrow 61, Fig. 10, while element 55 simul taneously moves upwardly and to the left as indicated by arrow @322. After this relative movement has taken place the outer ends of the type bars on the right side of segment 5% will now be supported by the right hand portion of element 55, as illustrated in Fig. 11, while the outer ends of the type bars on the left side of segment 50 will be supported by the left hand portion of the element 56. The kinetic energy of said actuated type bar is thus dissipated by being made to induce a small relative lateral displacement of both of said head rest elements 55 and 56 and a relatively small arcuate oscillatory movement of the unactuated type bars, thereby all but eliminating the tendency for said actuated type bar to rebound. A corresponding damping action will occur when an actuated type bar on the left side of segment 50 returns and strikes the head rest element 55, Fig. 10. As each successively actuated type bar strikes head rest 54, the elements 55 and 56 will be alternately shifted back and forth between the respective relative positions shown in Figs. 10 and 11. It will be understood that the extent of relative movement of said elements 55 and 56 diagrammatically shown in Figs. 10 and 11 has been greatly exaggerated for the purposes of clarity in explanation. In practice said relative movement amounts to only a small fraction of an inch and is such as to impart the desired small-amplitude oscillatory motion to the type bars.

While several embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that numerous variations and modifications may be made in the particular construction without departing from the underlying principles of the invention. It is therefore desired, by the following claims, to include within the scope of the invention all such variations and modifications whereby substantially the results of the invention may be obtained by the use of substantially the same or equivalent means.

The invention claimed is:

1. In a typewriter having a frame, a segment operatively supported in said frame, and a plurality of type bars pivotally mounted on said segment; the improvement comprising a first type bar head rest element adapted to underlie and normally yieldably support at least some of said type bars when the latter are in their respective atrest positions, a second head rest element adapted to structurally underlie said type bars and to operationally engage and support the latter after a predetermined amount of yielding of said first head rest element, and means for supporting said head rest elements in operative relation to said segment.

2. Apparatus as defined by claim 1 wherein said head rest elements are relatively positioned so as to normally engage the outer ends of some of the type bars and the intermediate portions of other of said type bars.

3. Apparatus as defined by claim 2 wherein said head rest is rotatably yieldable when struck by any of said type bars.

4. Apparatus as defined by claim 3 wherein the rotative movement of one of said head rest elements occurs in response to the yielding movement of the other of said head rest elements.

5. Apparatus as defined by claim 4 wherein said head rest includes means for interconnecting the respective mutually adjacent ends of said elements, said interconnecting means being pivotally mounted on said supporting means.

6. Apparatus as defined by claim 5 wherein the pivotal axis of said head rest is substantially horizontal.

7. In a typewriter having a frame, a segment operatively mounted on said frame, and a plurality of type bars pivotally mounted on said segment; the improvement comprising a yieldable first head rest element normally supporting at least some of said type bars, a second head rest element operatively disposed just below the respective normal positions of said type bars so that at the end of the return stroke of any given one of said type bars said one type bar may sequentially engage said first and Second head rest elements in predetermined sequence,

and means in said typewriter for operatively supporting said head rest elements.

8. Apparatus as defined by claim 7 wherein said second head rest element comprises a plurality of rigid damping tabs the ends of which are respectively spaced a slight distance below the lower edge of the intermediate portions of said type bars.

9. In a typewriter, a frame, a segment operatively supported in said frame, a plurality of type bars pivotally mounted on said segment; the improvement comprising a first head rest element operatively supported with respect to said segment, said head rest element being disposed so as to underlie and adapted to normally support the respective outer ends of at least some of said type bars, and a second head rest element operatively supported with respect to said segment, said second head rest element being disposed so as to underlie and be engaged by any type bars which have struck and yieldably displaced said first head rest element.

10. Apparatus as defined by claim 9 wherein said head rest elements are pivotally interconnected for relative lateral movement.

11. Apparatus as defined by claim 9 wherein both of said head rest elements remain in temporary arresting engagement with any one returning type bar after the latter has engaged said second head rest element.

12. Apparatus as defined by claim 9 wherein said head rest elements are interconnected for arcuate movement about a common axis.

13. Apparatus as defined by claim 9 wherein the respective ends of said head rest elements are movably interconnected for rotational movement about two different pivot axes.

14. In a typewriter having a segment, and a plurality of type bars pivotally mounted on said segment; the improvement comprising first and second head rest elements each adapted to underlie said type bars, means interconnecting said head rest elements, and means in said typewriter for pivotally supporting said last mentioned means in operative relation to said segment and type bars.

15. Apparatus as defined by claim 14 wherein the pivot axis of said pivotally supporting means is nearer to the plane of one of said head rest element-s than to the plane of the other of said head rest elements.

16. Apparatus as defined by claim 14 wherein said interconnecti ng means comprises a pair of links which articulately connect the respective mutually adjacent ends of said elements.

17. Apparatus as defined by claim 16 wherein said pivotal supporting means are bent so as to provide two pivot axes which are disposed at an angle with respect to the horizontal.

18. In a typewriter having a frame, a segment operatively supported on said frame, and a plurality of type bars pivotally mounted on said segment; a head rest comprising a pair of arcuate elements, means for mutually fixedly securing the respective adjacent ends of said elements, and means for pivotally supporting said elements in underlying relation to said type bars.

19. Apparatus as defined by claim 18 wherein said securing means are provided with looped portions, and wherein said supporting means comprise a pair of arms which are secured to said segment and which are provided with pivot studs that respectively operatively engage said looped portions.

No references cited. 

